1.   Five minutes before the procedure a pulse oximeter was attached to the right index finger, and a blood pressure cuff for automated readings to the right arm.

2.   A pulse oximeter, which is clipped to a finger or toe, measures blood oxygen levels.

3.   Doctors have long used devices called pulse oximeters that measure oxygen saturation in the blood of children and adults.

4.   The OxiFirst, like other pulse oximeters, works by measuring light waves passing through the skin.